Western blot of rat caudate lysate showing specific immunolabeling of the ~32k DARPP-32 phosphorylated at Thr75 (Control). The phosphospecificity of this labeling is shown in the second lane (lambda-phosphatase: Î»-Ptase). The blot is identical to the control except that it was incubated in Î»-Ptase (1200 units for 30 min) before being exposed to the Anti-Thr75 DARPP-32. The immunolabeling is completely eliminated by treatment with Î»-Ptase.